Researchers at the University of Georgia and two research institutions in Australia say they found that children with high waist circumference measurements were five to six times more likely than children with smaller middles to develop metabolic syndrome by early adulthood. Metabolic syndrome is a cluster of risk factors associated with long-term development of very serious health issues, such as coronary artery disease, stroke, and type 2 diabetes.

The researchers used data collected as part of a 20-year follow-up of 2,188 Australians aged 7 to 15 who participated in a national childhood health and fitness survey in 1985. After they became adults, subjects attended one of 34 study clinics, where they underwent a range of health and fitness assessments.

Participants with waist measurements in the top 25% for their age/gender during childhood were five to six times more likely to be classified with metabolic syndrome by the time they were 26 to 36 years old, compared to children with low waist circumference (those in the bottom 25%).

"We wanted to identify which clinical measures of childhood body composition best predicts long-term cardio-metabolic health risks," study author Michael Schmidt, PhD, of the University of Georgia's department of kinesiology, says in a news release. "We were able to compare a wide range of body composition measures and found that waist circumference seems to be the best measure to predict risk."

Schmidt says the study findings should make it easier for doctors and other health care providers to identify children at highest risk for future health problems in a simple and cost-effective manner.

Most previous studies have relied on the use of BMI, which is a ratio of weight to height, as the main measure of childhood obesity. Although BMI is useful, it doesn't distinguish between fat and non-fat weight or indicate where the fat is located.

Waist circumference measurements, on the other hand, capture the amount of fat that is located centrally in the body, which previous research has shown is particularly detrimental to cardio-metabolic health.

"Waist circumference is a more direct measure of centrally located fat -- including the amount of visceral fat -- which is more strongly related to adverse health conditions such as insulin resistance and elevated triglyceride levels," Schmidt tells WebMD.

Schmidt says introducing a waist circumference measuring system in schools may be controversial because of possible stigmatization. But such a system, he says, could provide a chance to identify at early stages children at highest risk for future health problems because of excess body fat.

"I think parents would want to know if their child was five to six times more likely to have early cardio-metabolic health problems," Schmidt says.

The study is published online in the International Journal of Obesity.

SOURCES: News release, University of Georgia.Schmidt, M. International Journal of Obesity, October 2010.Michael Schmidt, assistant professor, University of Georgia department of kinesiology.